Is the missing mass really missing?

Many physicists are nowadays convinced that some form of dark matter has to exist to explain for instance the discrepancy between the flat rotation curves of stars within a galaxy and the rotation curves expected from Kepler's third law.
Here, I want to argue that this whole reasoning should be reconsidered : What one needs to explain the galaxy rotation curves is a modification of Newton's law by taking into account the energy density of the vacuum.

Using this new concept of gravitation, a modification of Newton's law for gravitation is obtained (see http://arxiv.org/ftp/arxiv/papers/0712/0712.1110.pdf ) which explains the flat galaxy rotation curves, the Pioneer anomaly and the occurrence of voids. This theory is fundamentally different from the MOND theory. It rests on basic physical principles and predicts that the rotation velocity will drop to zero at some determined large distance. It can also explain the Pioneer anomaly and the foamy distribution of galaxies (along voids). Based on a newly derived equation of state of the vacuum, The Tully-Fisher relation could be derived. Further, it was found that the fine structure constant relates the vacuum energy density to the mass energy density of the universe.

The above paper, entitled "Vacuum Modified Gravity as an explanation for flat galaxy rotation curves" is an extension of a previous paper, namely:

In reference (R. Van Nieuwenhove, Quantum Gravity ; a Hypothesis, Europhysics letters, 17 (1), pp. 1.4, 1992), it was argued that mass corresponds to a state of the vacuum. However, the vacuum itself was not well described. Below, a more fundamental description of vacuum and matter is provided: